Endothelial dysfunction induced by post-prandial lipemia: complete protection afforded by high-intensity aerobic interval exercise.

OBJECTIVES: This study was designed to study the effect of exercise and a high-fat meal (HFM) on endothelial function.

BACKGROUND: Post-prandial lipemia and exercise oppose each other in terms of cardiovascular risk; however, the mechanism of their interaction is not well understood.

METHODS: Endothelial function was assessed by brachial artery flow-mediated dilation (FMD) in 8 healthy men before and after an HFM preceded (16 to 18 h) by rest, a single bout of continuous moderate-intensity exercise (CME), and high-intensity interval exercise (HIIE).

RESULTS: Before the HFM, initial brachial artery diameters were similar in all trials (0.43 +/- 0.04 cm), but after the HFM, basal diameter decreased only in the control (0.39 +/- 0.03 cm) and CME (0.38 +/- 0.04 cm) trials. Before the HFM, FMD/shear was improved by a single bout of CME (+20%, p < 0.01) and HIIE (+45%, p < 0.01; group differences, p < 0.01), with no effect in the control trial. After the HFM (30, 120, and 240 min), FMD decayed to a lesser extent with CME, but in a similar fashion to the control trial. In contrast, FMD in the HIIE trial remained elevated following the exercise despite a clear meal-induced lipemia. Although there were no correlations between vascular function and food-induced markers of cardiovascular risk, antioxidant status was strongly correlated with FMD (r = 0.9, p < 0.001).

CONCLUSIONS: These findings reveal a clinically relevant protective effect of acute exercise on the vasculature that is clearly exercise intensity dependent and tightly related to exercise-induced antioxidant capacity. (Endothelial Dysfunction Induced by Postprandial Lipemia; NCT00660491).